^^^^ 



THE DALLES DAM 



M^NARY DAM 



Figure 5. — Upper portions of intake frame in fishing 

 position at Tlie Dalles Dam and MeXary Dam. Note 

 liingetl screen used at McNary Dam to ensure that fish 

 near the ceiling of the intake did not escape the top net 

 by swimming up into the gatewell. 



DESIGN OF EXPERIMENTS 



Experiments at The Dalles Dam measured (1) 

 diel movement and (2) vertical distribution of 

 tingerlino: salmonids in the turbine intakes. An ad- 

 ditional experiment provided infonnation on the 

 vertical distribution of fingerlings at McNary 

 Dam. 



THE DALLES DAM EXPERIMENTS 



In botli experiments at The Dalles Dam, the 

 fyke nets were ti.shed in the center intake (B) of 

 turbines at both ends and at the mjddle of the part 

 of the powerhouse that contained operating tur- 

 bines. Turbines 1 to 10 operated continuously; tur- 



bines 11 and 12 operated intermittently; turbines 

 13 tlirough 22 had not been installed. At the be- 

 ginning of each fishing period, the turbine was set 

 to discharge about 310 c.m.s. (cubic meters per 

 second), producing a water velocity of about 1.2 

 m.p.s. (meters per second) in the zone strained by 

 the nets (measured without the nets in place). The 

 gatewell involved during a test was imcovered for 

 the entire test period. 



The salmonids were classified into two major 

 size groups. Fish in the smaller group (under 80 

 mm. fork length) were termed O-group, or first 

 year of life. Periodic examinations indicated this 

 group was composed almost exclusively of juve- 

 nile chinook salmon {07icorhynchii,s tshawytscha) . 

 Fish SO mm. and longer were classed as I-group 

 (second year of life or more) and identified by 

 species. Catches of I-groui5 salmonids during the 

 experiment on diel movement included chinook 

 salmon and steelhead trout (Sahno gairdneri). 

 Ammocoetes of the Pacific lamprey {Lampetra 

 tridcntata) also were caught. Catches made during 

 the study of vertical distribution included I-grouj^ 

 sockeye salmon {0. nerka) in addition to the 

 species mentioned above. 



The first experiment (April 7-27, 1960) con- 

 sisted of 18 tests to study diel movement of juve- 

 nile salmonids in turbine intakes. Each test was 

 composed of one day- and one night-fishing pe- 

 riod in the same intake within a single 24-hour 

 period. Day fi,shing a\'eraged IOI/4 hours within 

 the 12-hour period, 7 a.m. to 7 p.m. Night fishing 

 averaged 101/4 hours within the 12-hour period, 

 7 p.m. to 7 a.m. Tests in each area of the power- 

 house were made at 2- to 6-day intervals, condi- 

 tions permitting. Five tests were made at unit 1, 

 seven at unit 5, and six at units 10 and 11 (fig. 2) . 



In the second experiment (April 28 to May 12, 

 1960), 14 tests were made to sample the vertical 

 distribution of fingerling salmonids. Each test 

 was composed of a single fishing period, averag- 

 ing 16 hours within the 17-hour period from 3 :30 

 p.m. to 8 :30 a.m.'* Tests wei'e made in each of three 

 areas of the powerhouse; five in unit 1, six 

 in units 5 and 6, and three in units 10 and 12. 

 Tests in a single area were spaced at least 3 days 

 apart. 



t' This fishing period was chosen to allow personnel of the U.S. 

 Arnij- Corps of Engineers to Install and remove the intake frame 

 without seriously disrupting their normal work schedule. 



JUVENILE ANADROMOUS FISH IN TURBINE INTAKES 



603 



